Impact of hydrogen-rich gas mixture inhalation through nasal cannula during post-exercise recovery period on subsequent oxidative stress, muscle damage, and exercise performances in men
Shibayama Y et al. · Med Gas Res. 2020;10(4):155–162.
What kind of evidence is this?
Human
Randomized double-blind placebo-controlled crossover repeated-measures study
Exercise and recovery
Inhaled H₂
Not reported in this record.
Not reported in this record.
Methods at a glance
Healthy physically active young men able to perform high-intensity cycling
8 participants
60-minute post-exercise inhalation in each condition, separated by more than one week
A hydrogen-rich H₂/O₂ gas mixture was inhaled through a nasal cannula for 60 minutes during recovery after strenuous treadmill running and squat jumps.
H₂/O₂ gas mixture — H₂ and O₂ were co-delivered, not H₂ alone. It is an oxyhydrogen mixture, but not the exact 66.666% H₂ / 33.333% O₂ Brown’s-gas proportion.
Generator outlet: 68.0% H₂ and 32.0% O₂. After dilution with room air during spontaneous breathing, the paper estimated inspired fractions of at most 4.08% H₂ and 21.57% O₂.
1,224 mL/min H₂, calculated from the reported total generator flow of 1,800 mL/min × 68.0%.
576 mL/min O₂, calculated from the reported total generator flow of 1,800 mL/min × 32.0%. The actual inspired O₂ fraction was estimated at no more than 21.57% because room air was entrained.
Ambient air delivered at the same total generator flow of 1,800 mL/min through a matched device
Outcomes and reported result
Oxidative-stress and muscle-damage markers, countermovement jump, knee-extensor strength and sprint-cycling performance
Compared with placebo, the H₂/O₂ mixture attenuated the rise in urinary 8-OHdG and the reduction in countermovement-jump height. Other measured performance, blood oxidative-stress and muscle-damage outcomes did not differ.
Gas composition, total flow, calculated component flows, methods, principal results, funding and conflicts checked in the open-access full text; independent appraisal remains incomplete.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
Very small male-only study. Because the intervention co-delivered O₂, the isolated effect of H₂ cannot be established. Helix Japan funded the study and supplied the gas generator.
Healthy physically active young men during short-term recovery from the study’s strenuous exercise protocol.
Not reported in this record.
Not reported in this record.
Not reported in this record.
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 33380581 · DOI: 10.4103/2045-9912.304222
Open-access full text is available through PMC.
Open-access PMC full text and PubMed bibliographic record. Component flows are transparent calculations from the article’s reported total flow and gas percentages.
2026-08-10